A backlight for illuminating a liquid crystal cell is used in a liquid crystal display, and an edge light type backlight is adopted in a liquid crystal monitor and a direct type backlight is adopted in a liquid crystal television respectively depending on kinds of a liquid crystal display. A porous white film formed with air bubbles is generally used as a reflective film for these back-lights (Patent Document 1). In addition, a white film with ultraviolet absorbing layers laminated is proposed for preventing the film from yellowing due to ultraviolet rays radiated from a cold cathode fluorescent lamp (Patent Documents 2 and 3).
Various methods improving the properties of luminance for those reflective films are disclosed in these reflective films. For example, a method of providing a light shielding layer on the film plane opposite to a light source is disclosed for intending an improvement in luminance of an edge light type backlight (Patent Document 4). A method is also disclosed, such that spherical particles are provided on a surface layer having a binder therebetween, and refractive index difference between the spherical particles and the binder is selected, whereby a light diffusivity is controlled to improve a frontal luminance by a light diffuser sheet (Patent Document 5). In addition, a method is disclosed, such that in a reflective sheet of a direct type backlight, luminance unevenness in the backlight is improved by controlling diffusivity of the film plane on the light source side (Patent Document 6).    (Patent Document 1) Japanese Unexamined Patent Publication No. 8-262208    (Patent Document 2) Japanese Unexamined Patent Publication No. 2001-166295    (Patent Document 3) Japanese Unexamined Patent Publication No. 2002-90515    (Patent Document 4) Japanese Unexamined Patent Publication No. 2002-333510    (Patent Document 5) Japanese Unexamined Patent Publication No. 2001-324608    (Patent Document 6) Japanese Unexamined Patent Publication No. 2005-173546